I read some stuff about this, and it's hard to judge practicality without actually trying the thing. People are assuming two things:
It's new and made by engineers, so it inevitably won't be combat-ready.
or
It's new and made by engineers, so it will ineveitably be smartly designed and well suited to its purpose.
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Based on what I've read, there are a few practical advantages. It's wrinkle free, and easier to maintain. The collar prevents the interceptor vests from chafing the neck. The camo pattern is not ideal for any environment, but works pretty good in most places. The patches will be adapted to the new color uniform. The insignia is small and located on the chest, as it's harder for the enemy to identify at range. The new undershirt will be made of coolmax or some other wicking material, which ought to be more comfortable.
I honestly don't know about the velcro. I assume it would be the first thing to go if it was going to be a big problem. I think they're losing the buttons because they're harder to use (sometimes they just won't go in, and you have to fumble with it for a sec), and because they won't fall off.
I'm sure they'll get the kinks worked out in a year or two. Besides, it's better than
the new Air Force BDUs.